Magneto-optical recording medium
US6198704A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Feb 3, 2000 |
| Grant date | Mar 6, 2001 |
| Priority date | — |
| Expiry date | Feb 3, 2020 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG11B11/10515
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
A magneto-optical recording medium from which data is read by using a Kerr effect and which is capable of preventing signal imbalance caused from change in birefringence even in a system in which the amplitude of a reproduced signal is small and the spatial frequency of a shortest record signal train of the magneto-optical recording medium is 1.1.times.NA/.lambda.(line/m) or higher. The photoelastic coefficient of a substrate of the magneto-optical recording medium is 50.times.10.sup.-13 cm.sup.2 /dyne or smaller. The vertical birefringence of the substrate is 250.times.10.sup.-6 or smaller, the coefficient of water absorption of the same is 0.2 wt % or lower and the thermal coefficient of expansion of the same is 6.5.times.10.sup.-5 cm/cm.multidot..degree. C. or lower.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.